Patent
Temperature compensation in mass flow sensors employing the hot-wire anemometer principle
Thomas Bennohr,Michael Daetz +1 more
TLDR
In this paper, the authors used the sum of the voltage across the current measurement resistor and the voltage or a partialvoltage across the air flow measurement resistor as a measure of air flow.Abstract:
For determining the air mass flow in the intake pipe of an internal combustion engine by means of an electrical bridge, normally the current flowing through the current measurement resistor when balancing the bridge is evaluated as an indirect measure of the air mass flow. The primary measured quantity for the air mass flow is, however, the power converted at the air flow measurement resistor around which the air flows so that the indirect measurement always includes an error. To reduce this measurement error, the invention utilizes the evaluation of the sum of the voltage across the current measurement resistor and the voltage or a partial-voltage across the air flow measurement resistor as a measure of the air flow.read more
Citations
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Patent
Thermally balanced mass air flow sensor
TL;DR: In this article, a bi-directional mass air flow sensing device for measuring air flow, comprising a bridge circuit coupled across a voltage potential, is presented, where the bridge circuit comprises a first side including first and second temperature dependent sensor resistors connected in series and disposed on a thermally insulative substrate window in line with an air flow.
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Speed measuring device, method and vehicle speed measuring system
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Hot wire anemometer
TL;DR: A hot wire anemometer circuit has a calibrate subcircuit and an operate sub-circuit which are selectively invoked via a user-activate mode switch as mentioned in this paper. But the calibration subcircuits are not considered in this paper.
References
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Patent
Current controlled electronic circuit for a hot wire air flow meter
TL;DR: In this article, a current controlled electronic circuit for a hot wire air flow meter having a symmetrical bridge circuit to measure the mass of the airflow is presented, which requires very few adjustments to select a few resistors for obtaining a required temperature differential and compensation for variations in the temperature coefficient of resistance of both the heated and cold resistors.
Patent
Method of manufacturing a hot wire air flow meter
TL;DR: An exothermic resistor for use in a hot wire air flow meter is described in this article, where a tubular cylinder closed at its both ends is used as a support member.
Patent
Device for temperature compensation in a thermal mass flow meter
TL;DR: In this article, a thermal mass flow meter with heated and unheated electric resistors which are interlocked to a bridge, a variable temperature-independent electric resistor is connected in parallel to the bridge.
Patent
Device for measuring an air mass
TL;DR: In this paper, a bridge circuit is used to measure the air mass flow in a single-shot multivibrator with constant endurance, by means of the output signal of which a current source (Q) is switched in series with respect to the sensor resistor.